Carolina Alves Costa Silva’s research while affiliated with University of Paris-Saclay and other places

Carcinogenesis is associated with the emergence of protracted intestinal dysbiosis and metabolic changes. Increasing evidence shows that gut microbiota–related biomarkers and microbiota-centered interventions are promising strategies to overcome resistance to immunotherapy. However, current standard methods for evaluating gut microbiota composition are cost- and time-consuming. The development of routine diagnostic tools for intestinal barrier alterations and dysbiosis constitutes a critical unmet medical need that can guide routine treatment and microbiota-centered intervention decisions in patients with cancer. In this review, we explore the influence of gut microbiota on cancer immunotherapy and highlight gut-associated biomarkers that have the potential to be transformed into simple diagnostic tools, thus guiding standard treatment decisions in the field of immuno-oncology. Mechanistic insights toward leveraging the complex relationship between cancer immunosurveillance, gut microbiota, and metabolism open exciting opportunities for developing novel biomarkers in immuno-oncology.

Extracellular acyl-coenzyme A binding protein [ACBP encoded by diazepam binding inhibitor (DBI)] is a phylogenetically ancient appetite stimulator that is secreted in a nonconventional, autophagy-dependent fashion. Here, we show that low ACBP/DBI plasma concentrations are associated with poor prognosis in patients with anorexia nervosa, a frequent and often intractable eating disorder. In mice, anorexia induced by chronic restraint stress (CRS) is accompanied by a reduction in circulating ACBP/DBI concentrations. We engineered a chemical-genetic system for the secretion of ACBP/DBI through a biotin-activatable, autophagy-independent pathway. In transgenic mice expressing this system in hepatocytes, biotin-induced elevations in plasma ACBP/DBI concentrations prevented anorexia induced by CRS or chemotherapeutic agents including cisplatin, doxorubicin, and paclitaxel. ACBP/DBI reversed the CRS or cisplatin-induced increase in plasma lipocalin-2 concentrations and the hypothalamic activation of anorexigenic melanocortin 4 receptors, for which lipocalin-2 is an agonist. Daily intravenous injections of recombinant ACBP/DBI protein or subcutaneous implantation of osmotic pumps releasing recombinant ACBP/DBI mimicked the orexigenic effects of the chemical-genetic system. In conclusion, the supplementation of extracellular and peripheral ACBP/DBI might constitute a viable strategy for treating anorexia.

2572 Background: The gut microbiota influences the cancer immune set point and response to immune checkpoint inhibitors (ICB), participating in the differentiation and function of T cells. We aimed to investigate the potential impact of microbiota-specific circulating memory T cells in cancer immunotherapy. Methods: NCT04567446 provided longitudinal blood samples (T0, before starting ICB until 1.5 months; T3, between 3 and 5.5 months) from patients with lung (NSCLC) and kidney (RCC) during ICB therapy (alone or combinations) in France. Different pools of harmful (ENTERO: Enteroclosterspp, Hungatella hathewayi, VEILLEG: Veillonella spp, Eggerthella lenta and KLEBC: Klebsiella pneumoniae, Escherichia coli, Fusobacterium nucleatum (Fn)) or single beneficial (Akkermansia spp. (Akk), Faecalibacterium prausnitzii ( Fp)) pasteurized bacteria (ppB) were used to stimulate whole blood sample (22h). The secretion of CXCL13, IL-17 (ELISA) and IFNg (VIDAS) was quantified at baseline and longitudinally to characterize memory T FH , T H 17 and T H 1 responses, respectively and analyze the effects of antibiotics. Progression-free survival (PFS), overall survival (OS) were assessed according to bacteria-specific T cell responses. Results: From Mar. 2023 to Jan. 2024, a total of 75 patients were screened and 39 patients enrolled in this analysis (54 assessed samples). Median age was 66yr, 72% were male, 74% had NSCLC, 26% had RCC and 78% were treated in first line. Median progression-free survival was 5.3 months (0.9-12.4); median overall-survival was 5.9 months (1.5-12.4). Firstly, we analyzed the 33 samples at baseline. 15% of patients harbored Akk-specific T FH memory responses and those patients with CXCL13 secretion superior to the median of the cohort tended to exhibit longer PFS (p=0.064) while 54% of patients harbored KLEBC T FH memory responses that were clinically irrelevant. 15% of patients harboring circulating Akk-specific T H 1 memory responses had a shorter OS (p=0.055) while VEILLEG or KLEBC-specific T H 1 responses detected in 24% and 42% cases were clinically irrelevant. 26/32 patients who did not show Akk-specific T H 17 responses had a better OS. ATB tended to decrease bacteria-specific CXCL13 and IFNg responses but increased T H 17 memory T cells. While boosting the systemic T H 1 TCR tonus (IFNg secretion by fresh blood T cells stimulated with the positive control (mitogen)), ICB decreased the most prominent reactivities against KLEBC, VEILLEG or Akk, suggesting that bacteria-specific T cells may traffic to tumoral or intestinal locations. Conclusions: Although awaiting further validation and correlations with humoral IgG/A titers, circulating memory T cells against distinct commensals may be clinically relevant to predict benefit to immunotherapy, suggesting that such bacteria may invade tumor cells or share molecular homology with cancer antigens. Clinical trial information: NCT04567446 .

e20517 Background: Changes in gut microbiota may affect benefit from immunotherapy (IO). Gut dysbiosis can be identified by a fecal metagenomic signature (TOPOSCORE SIG1+ vs SIG2+), and/or by low levels of sMAdCAM-1. Recent studies showed that peripheral thyroid hormones conversion (fT3/fT4 ratio) has a strong prognostic role in various cancers, with low fT3/fT4 ratio predicting worse outcomes. Correlation between gut dysbiosis and metabolic stress, such as altered fT3/fT4 conversion, has not been investigated yet. Methods: A total of 77 lung cancer pts treated at Gustave Roussy Cancer Center with IO-based treatment with available measurement of baseline fT3/fT4 ratio, metagenomic data defined by TOPOSCORE category SIG1+ vs SIG2+, and/or level of sMAdCAM1 (low vs high according to the median) from the ongoing ONCOBIOTICS multicentric prospective study (NCT04567446) were selected. fT3/fT4 low vs high groups were defined adopting the median value as cut-off. Correlation between the fT3/fT4 ratio categories with TOPOSCORE and sMAdCAM1 were tested by means of a 2-sided chi-square test. Results: Baseline fT3/fT4 ratio and TOPOSCORE and/or sMAdCAM-1 data were available for 62 and 57 patients, respectively. A significant correlation was observed between fT3/fT4 ratio and TOPOSCORE category, with a higher proportion of SIG1+ pts (64.5%) vs SIG2+ (35.5%) in fT3/fT4 low group, and higher rate of SIG2+ (61.3%) vs SIG1+ (38.7%) pts in fT3/fT4 high group (p = .042). Similarly, a significant association was observed between low levels of sMAdCAM-1 and the fT3/fT4 low group (p = .047). In a independent dataset of 42 NSCLC treated with 2nd line IO, pts with low fT3/fT4 ratio had a mPFS of 1.7 mos and a mOS of 2.4 mos compared to 6.8 and 18.7 mos respectively for fT3/fT4 high pts (PFS HR = 0.56, 95%CI 0.30-1.05, p = .040; OS HR = 0.50, 95%CI 0.26-0.99, p = .030). Conclusions: Our data confirm the prognostic value of fT3/fT4 in progressing metastatic NSCLC and its correlation with gut dysbiosis markers. These findings open the way to further research for exploring specific therapeutic applications, such as tailored nutritional support and microbiota-driven interventions. Clinical trial information: NCT04567446 .

Tumor immunosurveillance plays a major role in melanoma, prompting the development of immunotherapy strategies. The gut microbiota composition, influencing peripheral and tumoral immune tonus, earned its credentials among predictors of survival in melanoma. The MIND-DC phase III trial (NCT02993315) randomized (2:1 ratio) 148 patients with stage IIIB/C melanoma to adjuvant treatment with autologous natural dendritic cell (nDC) or placebo (PL). Overall, 144 patients collected serum and stool samples before and after 2 bimonthly injections to perform metabolomics (MB) and metagenomics (MG) as prespecified exploratory analysis. Clinical outcomes are reported separately. Here we show that different microbes were associated with prognosis, with the health-related Faecalibacterium prausnitzii standing out as the main beneficial taxon for no recurrence at 2 years (p = 0.008 at baseline, nDC arm). Therapy coincided with major MB perturbations (acylcarnitines, carboxylic and fatty acids). Despite randomization, nDC arm exhibited MG and MB bias at baseline: relative under-representation of F. prausnitzii, and perturbations of primary biliary acids (BA). F. prausnitzii anticorrelated with BA, medium- and long-chain acylcarnitines. Combined, these MG and MB biomarkers markedly determined prognosis. Altogether, the host-microbial interaction may play a role in localized melanoma. We value systematic MG and MB profiling in randomized trials to avoid baseline differences attributed to host-microbe interactions.

Background Adulthood cancer results from (epi)genomic cellular changes associated with chronic inflammatory processes and maladaptive immune responses. Identifying sensors of health to disease transition culminating in early carcinogenesis beyond cell autonomous cues is an unmet medical need. A holistic view might help defining a high-risk model based on functional biomarkers amenable to personalized screening interventions and interceptive measures. Methods We conducted a prospective omics-based translational research study (PREVALUNG trial, NCT03976804) in 508 smokers with cardiovascular disease (CVD) aimed at predicting the 17 tobacco-associated cancers beyond the NLST, NELSON, PLCOm2012 screening scores. After inclusion, patients were scheduled for a low-dose chest CT-scan, and blood and feces samples were collected concomitantly. PREVALUNG omics-based sensors of health to disease transition included analytes related to inflammation, immunity, metabolism, metagenome, gut barrier, plasma proteomics, and clonal hematopoiesis. To validate our hypotheses, we investigated a Li-Fraumeni cohort of TP53 germline mutation carriers (LIFSCREEN trial, NCT01464086), and performed the same omics assessment on biological sample taken before cancer detection. Results We could estimate cancer risk of CVD patients based on 33 soluble markers and 2 clinical risk factors, with an AUC of 0.78 (0.67; 0.79). To challenge this model of inflammation-related cancer, we investigated a Li-Fraumeni cohort of TP53 germline mutation carriers who have a significantly increased lifetime cancer risk affecting multiple organ sites. Here, 13 soluble markers and 8 clinical risk factors predicted cancer with an AUC of 0.82 (0.66; 0.91). The functional pathways shared by both cohorts paving the way to carcinogenesis include the neutrophil/lymphocyte ratio, Th2 immunity (CCL24, CCL26, IL-4/IL-4R, IL-5, CCL11, CCL22, CD163, IL-33/ST2), inflammasome activation (IL-1b, IL-1R2, IL-1RN), gut barrier permeability (IL-33/ST2, CD14/LBP, MAdCAM-1, CCL25), cholesterol and biliary salt circuitries, tryptophan and vitamin B3 metabolism, polyamines and ketogenesis. Conclusions These two studies suggest that health to cancer transition results from coordinated and cumulative pathological failures of the meta-organism, amenable to biologically-guided prophylactic measures beyond life style changes. Acknowledgements MF, LZ and GK are supported by the SEERAVE Foundation, the European Union’s Horizon Europe research and innovation programme under grant agreement number No 101095604 [project acronym: PREVALUNG-EU, project title: Personalized lung cancer risk assessment leading to stratified Interception]. LIFSCREEN (NCT01464086) is funded by the French Ligue Contre le Cancer. Trial Registration Prevalence of Lung Cancer (PREVALUNG) study was approved according the French Jardé law; the study is referenced at the French ‘Agence Nationale de Sécurité du Médicament et des Produits de Santé’ (reference ID RCB: 2019-A00262-55) and registered on clinicaltrial.gov (NCT03976804).LIFSCREEN (ClinicalTrials.gov Identifier: NCT01464086). Ethics Approval Prevalence of Lung Cancer (PREVALUNG) study was approved according the French Jardé law; the study is referenced at the French ‘Agence Nationale de Sécurité du Médicament et des Produits de Santé’ (reference ID RCB: 2019-A00262-55) and registered on clinicaltrial.gov (NCT03976804).LIFSCREEN (ClinicalTrials.gov Identifier: NCT01464086).

Antibiotics (ABX) compromise the efficacy of programmed cell death protein 1 (PD-1) blockade in cancer patients, but the mechanisms underlying their immunosuppressive effects remain unknown. By inducing the down-regulation of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) in the ileum, post-ABX gut recolonization by Enterocloster species drove the emigration of enterotropic α4β7+CD4+ regulatory T 17 cells into the tumor. These deleterious ABX effects were mimicked by oral gavage of Enterocloster species, by genetic deficiency, or by antibody-mediated neutralization of MAdCAM-1 and its receptor, α4β7 integrin. By contrast, fecal microbiota transplantation or interleukin-17A neutralization prevented ABX-induced immunosuppression. In independent lung, kidney, and bladder cancer patient cohorts, low serum levels of soluble MAdCAM-1 had a negative prognostic impact. Thus, the MAdCAM-1-α4β7 axis constitutes an actionable gut immune checkpoint in cancer immunosurveillance.